Concrete constitutes the largest portion of construction and demolition waste generated each year in the United States. The Environmental Protection Agency (EPA) estimates that the total production of construction and demolition of concrete waste during 2015 was 381.8 million tons. In order to reduce the economic and environmental effects of waste concrete, researchers have begun to incorporate it into concrete mixtures. However, the inherent variability in mechanical properties between RCA sources makes it difficult to quantify the maximum permissible replacement of natural aggregate and the end-result properties of concrete. This project investigates the use of recycled concrete aggregates (RCA) obtained from a precast prestressed concrete plant in the manufacture of prestressed hollow core concrete slabs. Seven full scale slabs were tested in two ways (1) under long term static bending loads to investigate long term deflection behavior, and (2) under short term loading in bending, beam (one-way) shear and in punching (two-way) shear.
The results indicate that slabs with RCA generated larger long-term service deflections. With regards to strength testing the slabs with RCA performed just as well, if not better, than slabs with no RCA. Overall, this testing indicates RCA is a viable option in the efforts to help improve sustainability while maintaining a safe design.
Date of publication
Dr. Michael J. McGinnis, Dr. Michael V. Gangone, Dr. Yahya C. Kurama
Masters in Civil Engineering
Gomez Santana, Lizeth Marisol, "EFFECT OF RECYCLED CONCRETE AGGREGATES ON THE LONG-TERM, ELASTIC, TOTAL DEFLECTION AND STRENGTH OF PRECAST PRESTRESSED HOLLOW CORE CONCRETE SLABS" (2019). Civil Engineering Theses. Paper 16.